Try Googling "definite article"and "indefinite article". You should get many hits with a lot of information.
Student or Learner
I can't understand difference between Define article and Indefinite article.
Is there some rules when I use Define article and Indefinite article?
Welcome to the forum, Erica.
Click here and scroll down past the adverts. You'll find links to many previous threads on the subject.
I found that page by entering definite and indefinite articles in the Google Custom Search box near the top of the page.